Vibrators are a commonly used means for providing a silent alert, but may not be convenient in some frequently occurring situations. Consider, for example, the situation where a conventional, holster mounted pager is set to vibrate mode, and an alert is received when the user is in a car. Normally, the user would be alerted by the vibrator and would remove the pager from its holster to read the display. If the user is wearing more than very light clothing, it is commonly very difficult for the user to re-insert the pager into the belt worn holster. Tight mechanical coupling of the pager to the user is required to make the vibrator an effective alerting device. Thus, unless the pager is hand held, or returned to its holster, any subsequent alerts are likely to be missed. Further, the control means provided for changing the alert mode to audible are usually too complex to be undertaken while engaged in another absorbing task such as driving a vehicle.
Displays are commonly used on pagers to provide a capability for the transmission and reception of numeric and/or alpha-numeric messages.
For Numeric message pagers, with the display mounted on the top surface of the pager body, the direction of the pager display can be reversed, depending upon how the pager is carried. For example, pagers mounted in a top pocket offer a reversed display compared with a belt mounted device. In previous models (such as the SilCom SP200 numeric pager) this was accommodated by a means of control which provides for manual selection of the display direction by the user.
The displays of modern alpha numeric pagers are relatively large and are commonly mounted on the front face of the units. A holster with a belt clip is provided on some models so that the user may conveniently remove the pager from the belt mount to read messages. As alpha numeric pagers become smaller, it becomes more convenient for users to wear them such that the display can be read from the belt, without removal from the holster. This can be accommodated by the provision of a holster having a belt clip with a wide rotation angle of the belt clip as shown in FIG. 1. However, when so read, the display is inverted relative to the normal sense of the pager.